I'm experimenting with heat pipe based air-to-air heat exchangers for a DIY heat recovery ventilator.
I have a Chevy heater core that is the perfect size and configuration. I've been experimenting with refrigerant 134 in copper tubing, but fins to conduct heat into/out of the pipe are problematic. Heater core has the fin problem solved.
I'd like to use water as the working fluid in the core for leak/toxicity reasons.
I built a prototype using two computer processor heat sinks back to back. They're water based heat pipes, so there's a chance of the heater core working with water.
To have any chance of making it work, I have to get the partial pressure of air inside the core down to near zero. Pipes work pretty well under pressure, but flat pipes tend to crush under vacuum. There's lots of fin material for support, but not sure that's enough.
Anybody got any experience with this kind of thing?
The other issue is the pipe seal. The core has two pipes coming out of it that can rotate. I'm guessing there's some kind of washer seal that gets mashed together. The pipe is held in by crushing an outer rim to crimp it together. Fine for a heater, but this ain't gonna hold a vacuum for long.
Any suggestions on how I can seal up a half inch hole without melting the thing apart? I have some Welco 52 rod. With aluminum, there's a very fine line between no adhesion and oops...especially if 90% of it is under water so it won't melt.
And the point is moot if the pipes are gonna crush when I pull a vacuum on it. Suggestions?
Thanks, mike